The research in my group seeks to use the knowledge and techniques
of organic chemistry to prepare and characterize materials. These
materials are synthetic polymers or polymer additives. The materials
are chosen for their unusual structures, or for certain useful
or unusual properties, such as photosensitivity, molecular recognition,
and catalysis.

Microlithography is the process used for printing integrated
circuits. One requirement is a light sensitive material which
changes its reactivity or solubility on irradiation: this material
is known as a photoresist. The sensitivity of a
photoresist is the amount of light required to generate an image.
The resolution is the smallest feature which can be produced
in the resist. An improved photoresist will resolve smaller features
using less light. Light of shorter wavelengths allows smaller
features to be resolved, but usually at a cost in sensitivity.
Sensitivity can be increased by linking a catalytic process to
the photochemistry - a method known as chemical amplification.
We are currently studying a number of catalysts and materials
for chemically amplified photoresists: arylmethyl sulfones as
photoacid generators, quaternary ammonium salts as photobase generators,
and a variety of oligomeric structures as dissolution inhibitors.

Dendritic polymers or dendrimers are highly branched polymers
with a regular branching motif. These materials were first made
in the 1980s, and have many unusual properties. They
can be synthesized by divergent or convergent techniques. Our
research involves dendrimers made by the convergent technique,
which provides extremely monodisperse materials. We have made
significant advances in synthetic methodology, and are currently
working with photoactive labels to characterize the properties
of these materials in solution.

Molecular imprinting is a technique for creating polymers which
recognize other molecules. In the traditional method, a highly
cross-linked polymer is synthesized in the presence of a template
molecule. The resulting polymer is ground into a powder and thoroughly
extracted. The resulting material will display a high affinity
for the template moleculebecause there are cavities in the polymer
which match the template in size, shape, and polarity. Our research
in molecular imprinting seeks to devise materials that are easier
to make and can be erased and re-imprinted. This requires reversible
cross-linking interactions, whether hydrogen bonds or covalent
bonds.